Now that I am out of my '08 400h and into an '06 Highlander Hybrid I can appreciate differences in both. I think the RX was a tad faster but that could be change from the 330 to the 350 output that my HH doesn't have. Now that I don't have rain sensing wipers I miss them as well as the back-up camera. The HID headlights that were steering linked are to me more of a gimmicky kinda thing and I really didn't notice much if any of a difference. I DO miss my rear power rear tailgate, and the built in bluetooth but I found a device Soundfly by Satechi that works wonderfully for this. I also miss the door locks that engage when you put the car in drive and vice versa.
One thing I don't miss at all is the glare from the dash on the RX, it was awful and prevalent in most daylight situations, at least for me and my seating position. I think overall my driving position is better in the HH than it was in the Lexus and my monthly payment is MUCH improved for a similar experience.